Magnetic type fluid meter



ug- 10, 1954 A. F.v RoMANowsKl ET AL 2,685,796

MAGNETIC TYPE FLUID METER Filed oct. 2e, 195o 7 AMPLFIER a, 23) a7 F195.AMPUFIER 55 f5, QTY/a of L', "N 4 57 f r`| f I/ 56 7 F* TL 1li mh *l J[3 l: t 69 a7 7V /5 i V 3 al ,T-J "S AMPUFIER "au E 5 x a f a.' 1 l a ai! /g F13. E

l 4 l\ l 5 l A 7, /3 ALBERT E RoMANowsKl 5 LAuRyNcEAWx-:INECKE "9 f 37JNVENToR.

- ATTORNEY Patented ug. Al0, 1954 and ltirowser, Inc., Fort Wayne, Ind.,a

of Indiana corporation e6, 1950 serial No. 192,197

2 claims. (c1. s-sb More specifically, it' relates@ off/therme ns1-through a magnetici lld and theurrentorsignal f induced in` the liquidpicked `up,on;electrodes and measured to determine the velocity of theliquid.

It haben naar that the; ttt tas tra vention to proyidemeans.tfarginsuringrthat-.the

electric potential in the liquid adjacent the meter and on both sidesthereof is equal so that regardless of the grounding of the pipes orstream at any point in the system, the calibration of the meter andindicator will be unaffected and the indication will be a trueindication of the rate of flow of the liquid.

This object and others will become apparent from a study of thisspeclcation and the drawings which are attached hereto, made a parthereof and in which:

Figure l shows a form of grounding system which may be used when thepipe line is made of electrically conductive material.

Figure 2 shows a form of grounding system similar to that of Figure 1,but in which the metallic case directly connects the pipe line, and

Figure 3 shows a form of grounding system which may be used when thepipe line is made of electrically non-conductive material.

Referring iirst to Figure 1, the numerals I and 3 represent the pipeline which is of electrically conductive material in which is connected,by couplings 2 and 4, the meter tube 5 of non-conductive material, butwhich is preferably sheathed in a tube 'l of conductive material.

A case 9, preferably of magnetic material, such as steel, is suspendedby U-bolts II from the meter tube. The case adjustably supports on thebolts I3, an electro-magnet I5 having a core I1.

A pair of electrodes I9 are supported by the meter tube, are disposed ona horizontal 'diameter of the meter tube, are insulated from the shield'I and are connected by shielded leads 2| which are disposedsymmetrically in the magnetic iield, to an amplifier 23. The outputsignal from the ampliiierfis carried' by the' leads 25to' a voltmet'e'r'2'I-or -sotherfsuitable' instrumentation? Thusfar ther construction is`the same as'that in our prior pending application, identiiied above.'f-Bi-nding-posts '29"and^30,= 3I and; 32"or otherfasteningmeansfare*applied to thepipes' I and 3 respectively-- Theposts`are"preferably disposed insa'A common plane lwhichl 'includes' th'e`longitudinalaxis o'therpipesand tube 5*'and 'Whiolris preferablyperpendicular to the axes of the electrodes;y www .1 l s An electricconductor 33"connec`:ts"`thel posts 29 ande-'3 I awhile' 'a'second#conductor` 35 which h'as electrical characteristics4substantially""lile the conductor '33,connects'the' other posts 30 and32. The v conductors are preferably symmetrically ar ranged in the planeof the posts 29 to 32 about the" longitudinal axis 'of the'pipe. Eitheror both pipes `may 'be' grounded. `We have showna singlefpost '-31'mounted on andin electrical contact with'prpe`3a'd a wire'39 coni nectedto the post and ground 4I. The wires 33 and 35 are preferably attachedto the case by clips 43.

Operation In operation, the liquid may ow through the pipes I, 3 and 5in either direction. Any electrical potential which might be impressedon the pipes I and 3 or on the liquid will be grounded on both sides ofthe meter by the posts 29 to 32, wires 33, 35, post 31, wire 39 toground 4I.

The posts 29 to 32 are preferably located in a plane which isperpendicular to the common axis of electrodes I9 because this positionhas been found to be the most effective due apparently, to currentdistribution in the liquid.

With this arrangement it has been found that the signal does not varyfor the same flow so that when the register has been properly calibratedonce, and the meter zeroized in the manner disclosed in our aboveidentied application, changes in stray currents in the pipes do notaffect the signal.

First modified form In the modied form shown in Figure 2, the meter andmeter tube are the same as that just described in connection withFigure 1. The posts 29 to 32, Wires 33, 35 and clips 43 are eliminated.

Instead, the couplings 2 and 4 are brought inside the case 9 which makeselectrical contact with both of the pipes I and 3. The case, which is ofelectrical conductive material, is thus made to serve as the electricalconduit between the pipes Vwith the same results as described above inconnection with Figure 1.

Second modified form The meter and meter tube shown in Figure 3 are thesame as those indicated by the same numerals in the other gures. In thiscase hoW- ever, the pipes 5I and 53 are made of an electrical insulatingmaterial.

It is therefore necessary to provide electrodes 55 and 56, 51 and 58 inthe pipes 5I and 53 respectively, each of which is shown separatelygrounded at 59.

It is preferred that the electrodes in each pipe be disposed on a commondiameter and that the axes of the electrodes and of the pipes bedisposed in a common plane which is perpendicular to the diameter of themeter tube, which serves as the axis of the electrodes I9. Preferablycase 9 should have a ground I0.

It is, 0f course, obvious that the grounding system shown in Figure 1 or2 maybe used with the electrodes instead of the separate grounds and insuch cases it would be necessary to insure that an electrical conductiveconnection is made between electrodes 55 to 58 and that there is atleast one ground in communication with all of said electrodes.

Itis obvious that various changes may be made in the form, structure andarrangement of parts without departing from the spirit of the invention.Accordingly, applicants do not desire to be limited to the specificembodiment disclosed herein primarily for purposes of illustration; butinstead, they desire protection falling fairly within the scope of theappended claims.

What we claim to be new and desire to protect by Letters Patent of theUnited States is:

1. An apparatus for measuring fluid flow comprising an inlet pipe and anoutlet pipe formed of electrically conductive material, a conduitconnecting said pipes, said conduit comprising an inner, non-conductivelayer and an outer conductive layer connecting the conductive inlet andoutlet pipes, means for creating a magnetic eld across the crosssectional area of the conduit, electrodes extending through the conduitwalls and communicating electrically with fluid in the conduit, saidelectrodes being insulated from the conductive layer of the conduit, anelectrically conductive case enclosing the means for creating themagnetic eld and conductively connected to the pipes Von each side ofthe conduit, current measuring means connected with the electrodes byleads extending through the case and a ground connection to at least oneof said pipes.

2. An apparatus for measuring iluid flow comprising an inlet pipe and anoutlet pipe formed of electrically conductive material, a conduitconnecting said pipes, said conduit comprising an inner, non-conductivelayer and an outer conductive layer connecting the conductive inlet andoutlet pipes, means for creating a magnetic eld across the crosssectional area of the conduit, electrodes extending through the conduitWalls and communicating electrically with iluid in the conduit, saidelectrodes being insulated from the conductive layer of the conduit, anelectrically conductive case enclosing the magnetic eld creating means,leads irom the electrodes disposed symmetrically in the magnetic eld andextending through the case, the case being located substantiallysymmetrically with relation to the ends of the two pipes and theconduit, and a ground connection to the assembly of case and pipe ends.

References cited in the fue of this patent UNITED STATES PATENTS NumberName Date 2,315,805 Mayo et al Apr. 6, 1943 2,492,493 Misson Dec. 27,1949 OTHER REFERENCES Alternating Field Induction Flow Meter oi HighSensitivity, A. Kolin, Review of Scientific Instruments, vol. 16, No. 5,May 1945.

